Source: Michael Doyle Their Name Liveth For Evermore: The Great War Roll of Honour for Leicestershire and Rutland.
He was the son of John Joseph Brown an assistant schoolmaster, born 1861 in Aspatria, Cumberland and his wife Emma Jane, born 1865 in Roxby, Yorks. Sydney Wilfred was born in 1898 in Redcar, Yorks., he had one sibling, a brother Cecil E., born 1892 in Loftus, Yorks., in March 1901 the family home was at Daisy Cottages, Oxford Street, Coalville, Leics. In April 1911 Sydney was a scholar and was residing in the family home at 143, London Road, Coalville, Leics., together with his parents.

Source: Leicestershire War Memorials Project.
Coalville Times article - Friday September 27th, 1918

LOCAL CASUALTIES

Mr J. J. Brown, headmaster of All Saint’s School, and Mrs Brown of Oxford Street, Coalville, have been officially notified that their younger son, Second-Lieut. Sidney Wilfred Brown, of the East Lancashire Regiment, was wounded on September 5th and is missing. He is 19 years of age, and went into the army on leaving Coalville Grammar School. Mr and Mrs Brown’s elder son, Cecil Edmond, who was wounded near Kut, is now serving in India.

Research undertaken and submitted by Andy Murby 2/6/2018